The caller was probably using a public phone in the village of Bahar-ic-Caghaq, according to the Sunday Express. The newspaper reports that the caller claimed that he saw the missing British four-year-old in the village on Thursday.
Police think the mystery caller might have crucial information that might hold the key to finding Madeleine. They are also under the impression that he might have been using the public phone box in Bahar-ic-Caghaq to conceal his identity and location.
So far, police investigations in Malta have produced no results, a police spokeswoman said. "Nevertheless, the police will continue investigating this case."
Madeleine disappeared on 3 May from the holiday apartment where she was staying in Praia De Luz, Portugal.
Last week, detectives in Malta followed up claims by a Maltese woman who said she had seen a "look-alike" of Madeleine accompanied by a middle-aged woman near the City Gate in Valletta.
A British man staying in Malta also reported to officers that he had seen a girl matching Madeleine's description with a woman of either Spanish or Arabic origin.
Superintendent Pierre Calleja said police in Malta had received a report of a possible sighting. He said, "Subsequent to this report, a full scale police investigation and a magisterial inquiry were initiated. These investigations are actively in progress and all possible avenues are being pursued."
A spokesman for Madeleine's parents, Gerry and Kate McCann, said they would not be hasty in giving credibility to the claims at this stage.
In-Nazzjon, a Maltese newspaper, reported that two tourists told police they had seen a girl matching Madeleine's description in Valletta.
Other reports said four additional people had also come forward with possible sightings following this.
However, a spokeswoman for the McCann family has said they are not focusing on the sightings until more information was available from an official source.
"Their whole attitude from day one has been that they know there are going to be lots of bits of information, but if they expended energy on every single one of them what would they be like by now?" she explained.
Last Friday, Madeleine's family led supporters across 50 countries in marking the 50th day since her disappearance. They released 50 yellow balloons from the beach resort where their daughter went missing, and 49 other countries including England, Ireland, Argentina, USA, Singapore and Australia marked the day in the same way.
